I disagree. There are still enough search terms coming through to get an idea which terms are hot. In fact there are still huge chunks of search terms visible.
If you want to see which of your articles attracted readers, you have the option to look at the wordpress top post and pages section in your stats.
If you want to know which articles got attention by people using Google, you can open Google Webmaster Tools for further details. Open the tab search traffic, then search queries and then top pages.
There you can even open each page to get further query details that are hidden in our dashboard. Use this in addition to the wp stats.
Both together works very well.
The search engine term stats are still important. If you have huge traffic, you will still find a lot of informations. It´s not the time to kill it yet.